Tunnel-kiln.



G. H. BENJAMIN.

TUNNEL KILN.

APPLICATION FILED JAN-8.1918.

Patented Jan. 28,1919.

2 SHEETS-SHEET l- 6 5 22 //l I a I I I 7 "f, 7 1 25 INVEWTOR.

e. H. BENJAMIN TUNNEL KILN.

APPLICATION FILED JAN. 8,19l8.

2 SHEETS-SHEET 2.

FIGS.

w W m M a Q 3 firm. J E. M| P F 5 HOME 1 3. V m w 7 2 1 00 m w 5 8 U vmd 3 Z I W \\uw 4 m 05 w 3 w 9 4 I v E v w M A ,Wl kfl r \.l l, vn\/ w mw w, a 5 1 a U W u w d 7 2 n \v\, 00. 3. 3:3 MQ W M1 3 V 3 r UNITEDSTATES P TE T OFFICE.

enon'en 111mm BENJAMIN, or imwironx, N. Y.

TUNNEL-mu.

To all whom it may concern Be it known that I, GEORGE BEN- JAMIN, acitizen of the United States, residing at New York, in the county andState of New York, have invented certain new andnseful ImprovementsTunnel-Kilns,

- of which the following isa specification.

In a companion application, Serial No.

' 169,865 filed May 21-, 1917, I have described an improvement in tunnelkilns, in which the heat effects are due to heat radiated from a seriesof combustion chambers (in which gas and air are burned) located withinthe body of the kiln, and theair heated to a high temperature by meansof hot blast stoves arranged exterior to the'kiln. z

My present invention consists in a moat fied construction, wherein 1nplace of the combustion chambers located within the kiln, a singlecombustion chamber is located exterior to the inner wall of the kiln andheated by gas and air, and the heat from said inner wall radiatedintol-the. body of the kiln, and air heated by hot blast stoves,

as in myformer-application above referred to, introduced into, thebodyof the kiln.

The particular advantage of the construc-- tion shown in my presentapplication, over that shown in my former application, is found thefacttha't my improved eonstruction permits of more rapid and effectiverevolutionofthe heatjunits by combustion of the gas and air, than is thecase with the construction-of my former application, as well as otheradvantages, which ,will bereferred to in the specification."

i -The accompanying drawings will serve to illustrate 'my invention, inwhich:

Figure 1 is a transverse section taken substantially'on the 1ii1e'I-I ofFig. 3.

Fig. '2 is a longitudinal vertical section taken substantially on theline 11-11 of Fig. 3 is a horizontal sectiontaken substantially on theline.III-III of Fig 2.

.Fig. 4 is a'vertical'section taken substan tially on the line IV'IV ofFig. 3.

f In the drawings, 5 indicates the body of the kiln,.which is composedof the outer wall 6 and thejnner wall 17. Acombustion chamber -8 isprovided between the'walls 6 and 7, such chamber being snfiicientlylarge topermit free radiation of flame from the 1 gas andair burners 9.Situated in the hot- 10,v loosely piled, so as to provide air spaces tomof the chamber 8, are masses of brick mass of brick 10-isshown asarranged at an angle to the wall-[7 and in .frontof the orifice 12 ofthe gas and air burners9.

" In the operationofjthe kiln, a stream of gas'and air, ignlted,is-driven on the mass of brick. Under normal conditions the combust onof the gas and air at the burner orifice 1s instantaneous, and all theheat units .are liberated at once, at. which time the heated massofbrick 10 has no particular but only partial combustion, the streamcarrying the excess of carbono'n to; the'briok' work 10,"wher e it isdisassociated, tobe a1- most immediately burned in the upper-pop tion ofthe chamber 8. In-order to obtain Specification of Letters Patent. 'P tt 23, 191 Application filed January 8, 1918. Serial No. 216,897. i

11 between the brick. In the drawings this v eifect. .If, however, theproper proportions of gas and air introduced at the burner 9,

instantaneous combustion, it is necessary that the chamber 8'shall besufliciently'large to permit free evolution of the flame-due to thecombustion of the elements contained in the introduced gas and air. Imake theabove explanation, as it is ,notpossible to show, in-

The gas and, air burners 9 are situated atthe drawings, the parts, bysize, which will:- indicate the results which are to be obtained.

equal distances apart along the chamber 8.

1314= through branch pipes 15'16.con-

on the outside of the furnace, as indicatedjn Fig. 3, and are fed fromgas and air pipes trolled by valves 17-18. It will be under; stood thatby reason of the arrangement of; the burners, the temperature of thetreat-' 1.. ing chamber 19-can be regulated as desired?" 1 along itslength.

Connected to the upper portion of the com bustion chamber 8, is a flue20 which com-1 mnnicates with the cross fiues 21 which in i turncommunicate with down 'flu'es 22 connected to one or the other of thepairs ofv hot blast stoves 23-23 or 2 l24 (as shown in Fig. 3), whichstoves are in turn 'con- I? nected to chimney flue 25, the hot productsof combustion serving to heat the pair of hot blast stoves at the timein circuit, in passing through them, on the way to the chimney flues'25. Two hot blast stoves 23-23 and 24-24: are arranged on each, side ofthe kiln. Each of these stoves consists of a combustion chamber 26 and aheating chamber 27 The down flues 22 are shown asconnected through aflue 28 to the bottom of the i I their passage.

combustion chamber 26, andthe bottom of the heating cliam'ber27 throughflue 29,is

connected at one side, to the chimney flue 25, and at the other side toflues 80 arranged longitudinally on both sides of the bottom of thekiln, and having openings'31 com- I muni'cating with the interior ofthetreating chamber 19 of the kiln.

Situated in the lines 29 are butterfly valves 32'. When the valves arein the position shownin Fig. 3, the products of combustion from thecombustion chamber 8 pass through the hot blast stoves 23'24= to thechimney flue 25, heating the heating chamber 27 by Additional 'means maybe provided for. heating-the heating chamber 27, consisting of agas andair burner 33, as

indicated in dotted-lines in connection with hot blast stoves 24-'2P ofFig. 3. Connecte'd alsotothe lower part of the combustion' chamber26,'is a flue 134 co'minuni eating with'the'external air, or Withasource of "heated air.

.Situated between the down flues 22 and the air -flue. 34,-. is a damperWhen the damper -is in the' position shown at the left I of "Fig. v3,the air flue 36L is closed; When the damper 35 is inlt'he position shownat the.

right of Fig. 3, the. passage for the products of combustion .from thedown flues 22 is shown in the figure,'through.the flue 29, to

l .ofLfluesBG to" a longitudinal flue'37, closed at one end, butconnected atthe'other end toi longitudinal fiue 30,'thence. through openfings 3l'tobe emitted into the chamber 19- v of the treatingchamber 19.By regulating in the interior of the kiln.

From the above it Willbe seen that-When the hotfblast stoves 23 2 arebeing heated by the products of combustiom'the hot blast stoves 23*--24=are simultaneously heating air introduced through the airflues 34, andare, discharging the air-so heated into the treating chamber-1,9. Whenthe butterfly valves 32 are reversed, the operation of the pairsof.reversed-. 501

hot" blast stoves is correspondingly.

Forming a chamber l9 fconnected by means of a series the-'inlet'orificeof a pump 38.. The outlet orifice of -.the pump discharges into the at-"'mosphere, or ifdesire'd, into a recuperator to heat the air introducedinto the hot blast stovesfthrough the air flue 84. This arrangee p as itis believed that it Will be obvious to ment is obvious, and henceisnot-shown in the drawings. lounted Ion a trackway 19*,

are a series of trucks 40, on"whi ch are lo cated the materials 4:1 tobe treated. The top of each truck has formed. in it an open-- part ofthe chamber 19, but: situated below the bottom, of the kiln, is, a.

understood. The heat due to the combustion of gas'and air and set freein the combustion chamber 8, heats the Wall 7 the heat being transmittedto the interior of the treating chamber 19. At the same time, the

. air heated by the pair of hot blast stoves,

then in operation, is transmitted into the in terior of the treatingchamber 19 and passes to the top of the chamber along the Wall 7,gathering heat, and then moves downward under the action of the pump 38through the material 41 that is to be treated, through openings 42 toflues 36 to inlet of pump and i then to outletof pump. vAs aboveindicated,

in order to conserve heat, the air introduced into the chamber 19 may becirculated through a r'ecuperator if desired.

It will be seen from the above description, that the heating effects aredue, first, to the radiated heat from the Wall 7, and second,

to the heat conveyed by the air introduced into the'chamber 19, and thatby reason of the construction, the gases of combustion do not come incontact, with the material under treatment, the'chamber 19 actingas amuffle, so far as relates to the combustion taking place in thecombustion chamber '8,

and that theair introduced into the chamber 19, While serving as amedium for heating the material, also serves to absorb the moisture setfree from the material under treatment,'and to convey such moisture outI stance,.the chamber can be given a comparatively .loW- temperature atthe entrance end and a large body of air transmitted; the temperaturecan be increased at the center of the kiln and the transmitted airdecreased; the temperature can be quite cut off i i i at the exit end,While-the body of air transmitted can be materially increased, and thisair,.by m anipulating the hot blast stoves, v

'can-be cooler in temperature than the air admitted throughthe'hot'blast stoves at other portions of thelength of the kiln.

peratures, etc, along the length of the kiln,

those skilled in the art "to Which this inven? tion belongs. Having thusdescribed my invention, what I'claim is: I

I 1. In a tunnel kiln, the combination of a 120 i I havenot entered intodetailed descfip-- t'ions of the manipulations of valves", etc.,'

'the combustible bodies introduced into the treating chamber, aCombustion chamber arranged external to the treating chamber and adaptedto heat the treating chamber by radiation, means for introducing gas andair llnder pressure into the combustion chamber, means situated in thecombustion chamber adapted to accelerate the combustion of combustionchamber, and means for conveymg the products of combustion away from thecombustion chamber.

2. In a tunnel kiln, the combination of a treating chamber, a combustionchamber ar- --3. In a tunnel kiln, the combination of a treatingchamber, a combustion chamber arranged external to the treating chamberand 1,5 fradiation, means for introducing gas and adapted to heat the'treating chamber by air into'the. combustion chamber, means forconveying the products of combustion away from the com ustion chamber,and means for-causing heatedair to pass throughthe treating chamber.

ranged external to the treating-chamber, gas and air burners projectinginto the combustion chamber at. opposite sides of thetreating chamberrefractory heat radiating bodies situated int-l1 .ofthe gas and airburners, and an exit flue v 1 combustion chamber;

e combustion chamber in front for the. product's-- ofcombustion from the4. In a tunnel kiln, the combination of a' treating chamber,-acombustion chamber arrangedexternal to the treating chamber,

. combustion e amber meansforl'introducin'g gas'and air into the ,means'for conveying the products of combustion away from thefdcmbustionfchamber, air heating stoves arranged inpairs on each side.of-the kiln, means for causingthe products of combustion at one timetopass'through one pair of "stoves and to the chimney stack, and for 7causing air atthe same time .to pass through air delivered tothetreating chamber to pass the other pair of stoves to the interior of thekiln, together with means for, causing through and out fof the treatingchamber.

(5Q In a tunnel kiln, the combination of a treating chamber, airs-of hotblast stoves arranged on each slde of the exterior of the treatingchamber, ,means for heating one pair of stoves at one time, and meansfOI'dII- a. troducing at the same time air into the other pairof-"previously heatedhot blast stoves and causing" said air to bedelivered .into,

passed through anddrawnfrom the treating'chamber.

6. :In 'a'tunnel kiln, -the combination of -a com ustion chamber.

'eter at its lower ,into the combustion chamber, at such nected to thecombustion chamber.

treating chamber, a combustion chamber arranged to include the sidewalls and top of the treating chamber and sufiicient in dimensions topermit the free development of'heat' ,from the gaseous fuel introducedinto the combustion chamber, means for introducing combustible gaseousfuel into the combustion chamber at the lower part. thereof and at bothsides of the combustion chamber, means in the combustion chamber foraccelerating the combustion of the introduced gaseous .fuel and an exitflue for the products of ranged external to the treating chambeiysaidcombustion chamber of greater lateral diamortlons, on each side of thetreating cham er, than .at its upper portions or that part ove'r theroof of the treatlng chamber, gas and air burners projecting t1on havlngthe greatest lateral diameter,

masses of heat radiating material situated in I said combustion chamberinthe parts having the greatest lateral diameter, and-an exit flue forthe I products of combustion; con- 9. In a tunnel kiln oftheclassdescribed,

the combination of a. treating chamber, a

heating element, hot. blast stoves arranged" on each side ofthe'treating chamberin supplementing the, heat imparted by the pairs,means for alternately heating the hot blast stoves in-pairs by outgoingproducts of combustion from the heating element, and means connected tothe hot blast .stoves for products of combustion to 5 the hot blas'tstoves.

-In testimony whereoflI afiix my signame, in the presence of twowitnesses.

GEORGE HILLARD f Witnesses:

HELEN E. K'oELsoH, Lns'rnn BEARDSLEY.

